There are two major industries that use cyanide or cyanide compounds.
The first use in the mining industry, known as heap leaching, is a very economical and efficient way to separate small traces of gold from rock.
Ore is placed on a plastic pad and a weak cyanide solution is poured over it to pull the gold from the rock.
The waste from this process is discharged into self-contained ponds.
Environmental problems arise during times of heavy rainfall when ponds overflow and run into natural streams.
Environmentalists say the runoff could pollute drinking water and endanger salmon fisheries.
In addition, birds and other wildlife are endangered when they see the open blue cyanide ponds and stop to drink from them.
Another industrial use of cyanide, in the form of hydrogen cyanide gas, is in the plating industry.
There is a reported incident of five workers in Indiana dying of asphyxiation when working in an enclosed space in the presence of the cyanide gas.
A plating company in Hollywood, California was charged with dumping cyanide into the sewer system and with reckless storage of chemicals.
Another plating company in Burbank, California was closed by the EPA for reckless storage of chemicals including hydrogen cyanide.
The Japanese use hydrogen cyanide to manufacture tryptophan, an amino acid used as a nutritional supplement.
An unusual use of cyanide is to assist Cameroon villagers to gather honey from hives in tall trees.
Climbers stun the bees with smoking leaves and a cyanide compound.
